I have been really lucky (knocking on a lot of wood right now) to avoid injury this training cycle. The one thing that I have not been lucky on is chafing. Yes, ouch.
Normally I chafe in spots due to my sports bra (don't ask), but I have also chafed on my arms from my shirt and from my fuel belt on long runs. Luckily Band-Aid sent me some Friction Block to try just in time for the OBX half marathon. And I know what you are thinking, they have stuff called Body Glide for runners, but I just never felt like paying the $8 - $10 for a stick of it. You can get the Band-Aid Friction Block for approximately $4.99 and you don't have to get it from a sports store. They carry it at Walmart and Target.
And it worked like a charm, no chafing from my sports bra at all during the half marathon. The packaging says "invisibly prevents friction from shoes", but the label on the back says you can use it anywhere. So go buy some even if you don't run. I am going to use it with any new shoes I buy.
And also go buy these - they are freaking adorable (especially for a Disney family like we are...)